"Bombing Submarines with Magnets" Topic

"The magnets worked on the Soviets with the same maddening results. The crews of several Foxtrots were driven bonkers by the noise and returned to port rather than complete their cruises. Now, the Soviet navy could afford to furlough a sub or two, but NATO could not. Anti-submarine crews couldn't practice with floppy-magnets attached to their exercise targets."

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Mr. Roberts, eat your heart out!

So you make submarines easy to find by dropping magnetic noise makers on them.

And how did you find them and know where to drop the magnets?

Duncan

Well, the early Russian boats were noisy as hell, so relatively easy to detect on passive sonar.

Airplanes don't care about noise, so they tend to use active sonar. Or sometimes a mixed row of active and passive buoys, to try to sucker a sub into going right next to a passive buoy as a 'gap' in the row of active buoys.

The other way to find anything underwater is the Magnetic Anomaly Detector. A steel hull bends the earth's geomagnetic field, and what you do is look for a spot where the geomagnetic field is bent. Sure, there are lots of places where that happens. Shipwrecks, for example. But moving hulls make a bigger distortion.

My point, which I didn't make very clear, is that if you can find them to tag them you probably don't have to tag them.

Duncan

I guess you could tag them once you spot them, making them easier to track later. Or you could tag them with depth charges making them really easy to track later (they went down, mostly).

Not a war fighting weapon but an awesome cold war non leathal weapon.

Robert

"And how did you find them and know where to drop the magnets?"

Let's suppose that you know or suspect the general<\b> location of an enemy submarine. How many of these magnets can your ASW aircraft carry if it has a 5,000 lb payload? (The PB4Y-2 Privateer--Navy B-24 variant--had a maximum payload of 12,800 lbs.) Suppose that your target submarine has a beam of just over 20 feet. Assuming that there's some magnetic attraction, that you won't get perfect distribution, and you probably won't be dropping precisely across the Target's beam, let's say the the "hit zone" is 25 feet across. If the magnets weigh 10 lbs apiece, you can carry 500 of them and drop them in a line 2 nm long (12,500 feet). That's … not bad. Depth charges/bombs of the period had small effective radii, despite much greater weight, or were contact shaped-charges, which also had to be larger than 10 lbs.

ASW prosecutions took a long time and aircraft seldom prosecuted alone. Surface ships were effective killers, but not always great hunters. If the aircraft could tag the enemy sub and make evasion impossible, there was simply no way for it to escape the surface ships.